The magazine for the Umarex Racegun 4.5mm is an original replacement for the magazine included with the airgun.
The magazine, with a capacity of 22 BB' shotgun shells, has a solid metal body and a polymer foot for easy ejection from the pistol grip. Once the capsule is in place, it must be tightened with the lower knob, which will punch it through.
Note that once the capsule is installed in the magazine, it should not be kept in the magazine for more than 48 hours, as the gas pressure can permanently damage the valve seals.
The magazine donner can be locked in the lower position, this allows you to conveniently load BB'S balls by gravity directly from the pack.